Present semiconductor lasers have a thin lasing region. This thin region limits the output power and its beam divergence angle. The following formula relates laser diffraction-limited beam divergence angle to the output diameter of a lasing surface and its lasing wavelengths. EQU .theta.=2.44.lambda./d
Where
.theta.=radians PA1 .lambda.=Wavelength (meters) PA1 d=diameter of lasing surface (meters)
For present semiconductor lasers .theta. becomes large as a result of d being extremely small.
An array of present semiconductor lasers can be formed, but the physical size of the lasers limit the diameter of the lasing area. The lasing area is inefficiently scattered over the array and does not provide for concentrated laser light emission or a small diffraction-limited beam divergence angle. Therefore, there is a need for a method of making a layered semiconductor laser so that semiconductor lasing functions take place coherently over a large number of semiconductor junctions in a homogeneous manner.
Therefore, it is an object of this invention to provide a method by which a layered semiconductor laser can be made to provide a larger lasing area than presently available in semiconductor laser devices.
Another object of this invention is to provide a method of making a semiconductor laser device which has a smaller beam divergence angle than those of the present semiconductor laser devices due to the fabrication of the semiconductor lasers.
Still another object of this invention is to provide a method of making a semiconductor laser device that results in a laser that has a larger lasing area and thereby provides a higher power output capability.
Still another object of this invention is to provide a method of making a layered semiconductor laser in which the electrical leads are internal to the lasing volume of semiconductor material to provide increased laser efficiency by providing increased heat removal and low current losses.
Other objects and advantages of this invention will be obvious to those skilled in this art.